class S():
    # def __init__(self):
    #     print("ccc")
    def a(self,a1,a2):
        print(a1+a2)
        return
    def b(self,b):
        print(b)
        return
    def c(self,c):
        print(c)
        return
    def d(self):
        print("d")

s=S()
class aTest_app:
    list = [
        ["a", "1", "2", ''],
        ['b', "3", ''],
        ['c', "4", ''],
        ["d", '']
    ]
    def run_step(self,func,params):
        params = params[:params.index('')]
        if params:
            func(*params)
        else:
            func()
    def atest_case(self):
        for i in self.list:
            func=getattr(s,i[0])
            self.run_step(func,i[1:])
if __name__ == '__main__':
    app=aTest_app()
    app.atest_case()






